Control Theory in Government’s Economical Decisions
Researchers at K. N. Toosi University of Technology in collaboration with a group of economists from the Iranian National Tax Administration have developed a strategy that could predict government tax revenues for a better budget planning. In a study that outlines this strategy, the researchers found that a model for the tax system needs to be identified, not solely based on similar data in previous years. The traditional models don’t have reasonable accuracy due to the lack of considering other effective factors and uncertainties such as price changes, government policies and the rate of production boom. “If the governments could predict the amount of tax revenue, they could optimally allocate the available resources, so the rate of participation of people in public expenses would be determined – highly important for budget planning!”, says Dr. Hamid Khaloozadeh, professor of Control Systems and the Dean of the Faculty of Electrical Engineering at K. N Toosi University of Technology. It is clear that the tax system of a country is more complicated to be modeled using linear regression-based or classical methods. In addition, such systems are not either linear or stochastic. In fact, they belong to the non-linear systems spectrum which exhibit chaotic behavior. You may think they show totally random behaviors, but despite of their complexity, their behaviors could be modeled.
“Structures such as neural networks are reasonable for modeling such systems, especially when we use Fuzzy logic for modeling the uncertainties. Artificial Neural network Fuzzy Inference System (ANFIS) could be the optimum method we have used for modeling the desired system,” adds Dr. Khaloozadeh.
There are several methods such as Ant Colony Optimization, Genetic Algorithm Optimization and Particle Swarm Optimization for obtaining the parameters of the model which can be combined with identified model in order to predict all tax revenue resources. Results show that polynomial method is not strong enough for modeling, while the ANFIS-based methods are generally more beneficial.
These algorithms have been implemented such that you can choose the period of prediction and the method you prefer, as well as the type of the tax to be analyzed. The software has been initially implemented in MATLAB in order to allow for fast prototyping and testing. The result ultimately appears as two charts, one a graph based on the actual data of previous years, and the prediction chart as the output of the software. In the predicted chart, the results are reported with 95% confidence interval.
“As an example, supposed that we want to provide about 30% of the total budget of the country from the tax revenue resources. The software would calculate to what extent the direct or indirect tax should increase to meet our needs or how much each province’s ration is in this 30%.”
The paper detailing the proposed strategy – Tax revenues forecasting by applying PSO optimization algorithm, authored by Dr. Khaloozade in collaboration with Saeideh Hamidi, was recently published in the Journal of Economic Modeling Research. The developed software is currently being used in the Iranian Parliament as a decision support system.